According to the prior art, pumps such as diaphragm pumps are capable of suction of a medium in the input and delivery of the medium in the output. A reversal of the direction of the medium delivered is not possible in diaphragm pumps which have passive inlet and outlet valves.
It is further known from the prior art that the direction of flow in a fluid line may be reversed by combining two 3-way valves, where the valves are, as a rule, arranged side by side on connecting plates. The electrical connection is mainly effected by means of single strands which are united in a cable harness and then led to a connector plug.
A disadvantage here is that systems of this type are susceptible to vibrations, which frequently results in the single strands becoming detached. This may lead to disturbing failures of the equipment.
As an alternative, for reversing the flow of diaphragm pumps valves systems are used in which a single coil actuates an elastomer-sheathed control member, two valve seats being opened and two other valve seats being closed at a time. In this variant, the fluid space is sealed by axially clamped seals.
It is disadvantageous here that leakages may appear in case of thermal stress or mechanical influences.